Question

Match List I with List II

LIST I Complex		LIST II Colour
A.	Mg(NH4)PO4	I.	brown
B.	K3[Co(NO2)6]	II.	white
C.	MnO(OH)2	III.	yellow
D.	Fe4[Fe(CN)6]3	IV.	blue

Choose the correct answer from the options given below:

• A. A-II, B-IV, C-I, D-III
• B. A-II, B-III, C-l, D-IV
• C. A-III, B-IV, C-II, D-I
• D. A-II, B-III, C-IV, D-I

Answer 1

The Correct Option is B

Let's match the complexes in List I with the colors in List II by analyzing each compound:

1. Mg(NH₄)PO₄: This is magnesium ammonium phosphate, which is typically a white precipitate. Hence, it matches with II. white.
2. K₃[Co(NO₂)₆]: This is potassium hexanitritocobaltate(III), known to have a yellow color due to the presence of cobalt in the +3 oxidation state, which forms a yellow nitrite complex. Hence, it matches with III. yellow.
3. MnO(OH)₂: Manganese(III) oxide-hydroxide usually appears as a brown solid. Hence, it matches with I. brown.
4. Fe₄[Fe(CN)₆]₃: This is ferric ferrocyanide, also known as Prussian blue. It is well known for its deep blue color. Hence, it matches with IV. blue.

Based on the above analysis, the correct matching is:

• A. Mg(NH₄)PO₄ - II. white
• B. K₃[Co(NO₂)₆] - III. yellow
• C. MnO(OH)₂ - I. brown
• D. Fe₄[Fe(CN)₆]₃ - IV. blue

Thus, the correct answer is A-II, B-III, C-I, D-IV.